Assessment of Functional Outcomes Using the 6-Minute Walk Test in Cardiac Rehabilitation: Comparison of Patients With and Without Left Ventricular Dysfunction

Abstract Background The 6-minute walk test distance is frequently used to assess functional capacity of cardiac disease population. Nevertheless, anthropometric differences can confound or misestimate performance, which highlights the need for new parameters. This study aims to investigate the potential of the body weight-walking distance product (D.W), compared to 6-minute walk test distance, to predict exercise capacity measured by VO 2 on-kinetics in coronary artery disease (CAD) patients.Methods Cross-section study in a tertiary-care reference institution. Forty-six participants with multiarterial CAD with and without left ventricular dysfunction underwent a 6-minute walk test with simultaneous use of mobile telemetric cardiopulmonary monitoring to evaluate oxygen uptake (VO 2 ) on-kinetics and other cardiorespiratory responses.Results Perceived effort Borg for lower limb fatigue was only correlated with the D.W (p=0.007). The percent-predicted and actual distance were only modestly to moderately correlated with VO 2 on-kinetics (p<0.05). All the associations of VO 2 on-kinetics parameters were improved by showing a stronger correlation to the D.W (p<0.0001), which also had a larger effect size to identify differences between coronary disease patients compared to distance ( d =1.32 vs d =0.84).Conclusion The D.W demonstrates potential as a measure superior to the distance in determining VO 2 on-kinetics in participants with CAD with and without left ventricular dysfunction.

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Direct Myocardial Implantation of Human Fetal Stem Cells in Heart Failure Patients: Long-term Results

The Heart Surgery Forum ◽

10.1532/hsf98.20091130 ◽

2010 ◽

Vol 13 (1) ◽

pp. 31 ◽

Cited By ~ 13

Author(s):

Federico Benetti ◽

Ernesto Pe�herrera ◽

Teodoro Maldonado ◽

Yan Duarte Vera ◽

Valvanur Subramanian ◽

...

Keyword(s):

Heart Failure ◽

Stem Cells ◽

Cardiac Function ◽

Nyha Class ◽

Left Ventricular ◽

Long Term Results ◽

Walk Test ◽

The Mean ◽

6 Minute Walk Test ◽

Minute Walk

Background: End-stage heart failure (HF) is refractory to current standard medical therapy, and the number of donor hearts is insufficient to meet the demand for transplantation. Recent studies suggest autologous stem cell therapy may regenerate cardiomyocytes, stimulate neovascularization, and improve cardiac function and clinical status. Although human fetal-derived stem cells (HFDSCs) have been studied for the treatment of a variety of conditions, no clinical studies have been reported to date on their use in treating HF. We sought to determine the efficacy and safety of HFDSC treatment in HF patients.Methods and Results: Direct myocardial transplantation of HFDSCs by open-chest surgical procedure was performed in 10 patients with HF due to nonischemic, nonchagasic dilated cardiomyopathy. Before and after the procedure, and with no changes in their preoperative doses of medications (digoxin, furosemide, spironolactone, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, betablockers), patients were assessed for New York Heart Association (NYHA) class, performance in the exercise tolerance test (ETT), ejection fraction (EF), left ventricular end-diastolic dimension (LVEDD) via transthoracic echocardiography, performance in the 6-minute walk test, and performance in the Minnesota congestive HF test. All 10 patients survived the operation. One patient had a stroke 3 days after the procedure, and although she later recovered, she was unable to perform the follow-up tests. Another male patient experienced pericardial effusion 3 weeks after the procedure. Although it resolved spontaneously, the patient abandoned his control tests and died 5 months after the procedure. An autopsy of the myocardium suggested that new young cells were present in the cardiomyocyte mix. At 40 months, the mean (SD) NYHA class decreased from 3.4 0.5 to 1.33 0.5 (P = .001); the mean EF increased 31%, from 26.6% 4% to 34.8% 7.2% (P = .005); and the mean ETT increased 291.3%, from 4.25 minutes to 16.63 minutes (128.9% increase in metabolic equivalents, from 2.46 to 5.63) (P < .0001); the mean LVEDD decreased 15%, from 6.85 0.6 cm to 5.80 0.58 cm (P < .001); mean performance in the 6-minute walk test increased by 43.2%, from 251 113.1 seconds to 360 0 seconds (P = .01); the mean distance increased 64.4%, from 284.4 144.9 m to 468.2 89.8 m (P = .004); and the mean result in the Minnesota test decreased from 71 27.3 to 6 5.9 (P < .001).Conclusion: Although these initial findings suggest direct myocardial implantation of HFDSCs is feasible and improves cardiac function in HF patients at 40 months, more clinical research is required to confirm these observations.

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Prognostic role of results of dynamic capnography in integral assessment of parameters of respiratory system in 6-minute walk test in patients with chronic heart failure

I P Pavlov Russian Medical Biological Herald ◽

10.23888/pavlovj2020283290-299 ◽

2020 ◽

Vol 28 (3) ◽

pp. 290-299

Author(s):

Kira A. Ageeva ◽

Evgenii V. Filippov

Keyword(s):

Respiratory System ◽

Prognostic Significance ◽

Left Ventricular ◽

Left Ventricular Ejection ◽

Control Group ◽

Walk Test ◽

Ventricular Ejection Fraction ◽

6Mwt Distance ◽

6 Minute Walk Test ◽

Minute Walk

Aim. To study the prognostic value of the results of dynamic capnography in the complex assessment of parameters of the respiratory system in 6-minute walk test in patients with chronic heart failure (CHF). Materials and Methods. 73 Patients were examined: the group of study included 48 patients with IIA or IIB stage CHF (mean age 57.94.6 years, 23 men), the control group included 25 practically healthy volunteers (mean age 47.63.5 years, 9 men). The patients were conducted complex determination of parameters of the respiratory system: clinical scaling before and after 6-minute walk test (6MWT), instrumental examinations including spirometry, capnography and pulse oximetry before, during and after physical activity. The analysis of survival was conducted on the basis of the dynamic follow-up of patients within 5 years (60 months). Results. In the analysis of parameters of dyspnea at rest, all the parameters were higher in the group of patients with CHF (р0.05). The distance walked by the patients with CHF in 6 minutes was 488.2390.84 m, which was significantly less than in the control group (815.6053.89 m, р=0.009). Dyspnea as the cause of stoppage/slowing down of walking in 6MWT, was also more often recorded in patients with CHF (93.83.0% and 48.05.1%, р=0.049). Besides, in 6MWT the patients noted: weakness in legs (50.15.0% in the group of CHF and 40.05.0% in the control group, р=0.014), palpitation (29.04.6% and 20.04.1%, respectively, р=0.004). Worsening of dyspnea parameters in 6MWT was more evident in patients with CHF than in the control group (р0.01). In the CHF group, hypocapnic type of ventilation was revealed in 6MWT, analysis of РЕТСО2 trend graphs revealed a wave-like increase in the parameters, the so called periodic breathing (PB). CO2 trend was recorded in CHF group in 58.31.0% of cases (the difference with the control group with р=0.046), the trend of heart rate in 18.80.3% of cases (р=0.027). Cox proportional hazards regression analysis of mortality in patients with CHF showed a prognostic significance of a complex model comprising the following parameters of a patient: body mass index (р=0.005), left ventricular end-diastolic dimension (р=0.034), left ventricular end-systolic dimension (р=0.002), left ventricular ejection fraction (р=0.041), 6MWT distance (р=0.004), desaturation (р=0.009), and the presence of signs of PB during 6MWT (р=0.005). Model coefficients were statistically significant at р0.0001. Conclusions. Dynamic capnography and pulse oximetry allow to identify signs of PB in patients with CHF during 6MWT which may deepen a complex assessment of parameters of the cardio-respiratory system in patients with CHF in order to determine tolerance to physical exercise as well as the effectiveness of the conducted treatment. Complex assessment of survival of patients with CHF showed prognostic significance of the following parameters of a patient: body mass index, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, left ventricular ejection fraction, 6MWT distance, desaturation, PB during 6MWT.

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